Keyboard instrument



Sept. 13, 1932. E MQQR ETAL 1,877,526

KEYBOARD I NS TRUMENT Filed Aug. 25, 1930 5 Sheets-Sheet l W B 3 M A Fl] 3 75 R191 Sept. 13, 1932. MQOR ET AL 1,877,526

KEYBOARD INSTRUMENT Filed Aug. 25, 1930 5 Shees+$heet 2 g I In venfors Sept. 13, 1 932. E. MOOR ET AL 1,377,526

KEYBOARD INSTRUMENT Filed Aug. 25. 1930 5 Sheets-Sheet 3 Sept. 13', 1932 E. MOOR ET AL KEYBOARD INS TRUMENT Filed Aug. 25. 1930 5 Sheets-Sheet 5 as as 37 33 9 i &

Patented Sept. 13, 1932 UNITED STATES PATENT OFFICE I EMANUEL MOOR, OF MONT PELERIN, SWITZERLAND; CARL BECHSTEIN, JR., BER- LIN, AND HANS JOACHIM GRAVENSTEIN, OF GHARLOTTENBURG, GERMANY KEYBOARD INSTRUMENT Application filed August 25, 1930, Serial N0.

Key instruments are known in which a plurality of keyboards, for instance two, are provided, these being playable independently and v, the rear keyboard being given an independent tuning, for example one octave of difference as compared with the front when corresponding keys are struck.

In these the keys lying one behind the other in the same rows and arrangement work on in the same hammer systems.

It is further known by insertion of a coupler of known construction from the front keyboard to bring the higher toned octave into tune with the fundamental tone, so that the rear keyboard could be played by itself.

These known constructions have however the disadvantage of a somewhat heavy touch which is occasioned especially through the use of a bent one-piece lever for the keys of the rear keyboard, the bearings of which lever remain tilted. Again these levers are very liable to breakage, and repairs are inconvenient, time wasting and costly, as a renewal of Y asingle part makes it necessary to remove the keyboard.

Compared with these known constructions the present invention is differentiated in that the octave coupling is effected by means of a double armed push lever or pull member,

which from the fundamental. tones of each keyboard, after desired insertion in the mechanism of a pedal actuated coupling, is led in inclined direction from these the fundamental tones of each keyboard to the striking apparatus of the appropriate right hand lying keys.

A further characteristic of the invention is that for the direct operation of the right hand or higher note mechanism served for example by the upper keyboard a special connecting arrangement is provided so mounted and constructed that on the pressing of thefor exampleupper row of keys the same stroke and touch as with the lower keyboard is assured.

Further the invention is characterizedin that a striker for the hammer mechanism. has different contact points for the push members 60 of the octave and of the fundamental tone 477,738, and in Germany January 23, 1930.

keys and for the connecting member of the octave keys.

Through these improvements an exact and even touch of about grammes, per key is attained, as also by the coupling of the fundamental tones with the higher octave key levers. Still further the stability of the Whole lever construction is considerably increased and the fulcrum bearings so improved that the weakening of single levers by the strongest Stroke is impossible. Also in the hammer system the striker is so in contact at various points with the push or pull members that the wholeis balancedand the hammer strikes the string always with the same force or swing.

Our invention is illustrated diagrammat ically and by way of examples on the accompanying drawings, in which Figure 1 is a side-view of two keyboards arranged one below, and in front of, the other, together with, firstly, the appertaining transmission levers and; the means for engaging them at three points of the lifting member of the hammer system, and seconds ly, the coupling device; I

Figure 2 is a plan of'the members shown in Fig. 1; 1

Figure 3is an illustration similar to Fig. 1, but showing a modification in which the lifting member of the hammer system is engaged only at two points, the octave transmission is eflected by means of pull strings, and two curved members forming parts of the mechanism co-operate in such a manner that the push member engages the lifting member always with equal force;

Figure 4 is also an illustration similar to Fig, 1 and shows another modification in which pressure levers and pull levers are combined, each lifting member being subjected to pressure by the appertaining push member, as well as to a pull from above;

Figure 5 is a separate view of the righthand portion of Fig. 1, drawn to a somewhat enlarged scale;

Figure 6 is a plan of the members shown in Fig. 5; s

Figure 7 is a separate view of the lefthand portion of Fig. 1, also drawn to the somewhat enlarged scale;

Figure 8 is a plan of the parts shown in Fig. 7;

Figure 9 is an illustration similar to Fig. 1, showing a modification;

Figure 10 is an illustration similar to Fig. 2 and relates to Fig. 9;

Figure 11 is an illustration similar to Fig. 5 and Figure 12 is an illustration similar to Fig. 7, these two figures relating also to the modification shown in Fig. 9.

In the schematic showing of Figures 1 and 2, A and B are two keyboards arranged one behind the other.

The keys 1 of the front keyboard A are mounted on levers 2 which pass through to the hammer system and by their push ends 3 make contact with strikers 4 on the striking of a key 1, hammer 5 thus being swung against a string 6.

In the keyboard B the keys 7 are formed as one or double armed levers which are held in their rest position as usual by counterweights or springs at 8.

Below each key 7 is a bent lever 9 which is sufficiently out of balance and is borne in the fulcrum 10. By means of adjusting screws 11 the end of the lever can be adjusted in relation to a key 7 and the push member 12 on the lever end makes contact with the striker 4 at a higher position (see Figures 1 and 7 In sipite of the difference of contact points at the striker 4 the efiect of pressure remains the same.

By the bending of the lever 9 the same receives an inclined position (see Figures 2, 6 and 8) which leads it to the hammer system of the higher octave string, so that by striking a key of the keyboard B the octave tone is in unison with the corresponding key of the keyboard A to be struck for the fundamental tone. The two keyboards are thus independent and may be played singly or together.

At the forward part of every lever 2 of a key 1 is mounted a coupling member 13 which through a pull rod and angle lever arrangement is connected with a pedal 14.

These couplings may by suit-able arrangements be all connected to the pedal 14 or be connected thereto in groups.

Below lever 9 and fulcrumed on a special bench 15 is a lever 16 both sides of which are bent and sufficiently unbalanced (see Figures 1, 2, 5, 6, 7 and 8). Each of the series of levers 16 has the push end 17 which makes contact with the striker 4 at the third point thereon. (See Figure 2).

Each lever 16 is provided at its forward end with a tongue 18 which can be so adjusted by means of the adjusting screws 19, 20, that a full, exactly similar and synchronous stroke or touch of the fundamental tone and octave tone takes place together, the strings producing the coupling 13 has been put intooperation.

The coupling 13 can take other forms than that shown in Figure 5; the essential is that the key levers 2 with their connected push or pull members can be operated without interference with the keys 7 of the keyboard B as to playability of the latter.

In Figure 3 is shown another example of construction of the octave operating means as well as of the coupling as shown.

The method of operation of the keys 1, with the levers 2, push members 3 and coupling 4 remains the same. The touch on a key 7 however influences a lever system 21, 22, 23, 22 being a pull member, for instance a steel wire. The curved member 23 cooperates with the push member 24: in order to bring the striker 4 to the striln'ng point of hammer 5.

The coupling of the keys 1 is established through the lever 25, which has a like or similar adjustment to that of lever 16 in Figure 3.

In Figure 4 the old movement for the keys 1 is retained, whilst for the keys 7 a combined system of press and pull members should be employed. The keys 7 on being depressed contact with lever 26 and through counterweights or springs 27 are brought back to the rest position. Through angle levers 28 and 29 a pull is exerted on the striker 4 to cause the hammer 5 to strike as usual the string 6. Each lever 26 is provided on its free forward end with an adjusting arrangement, so that coupling 13 may be brought into action through the pedal 14.

Instead of the push and pull transmission described other forms may be employed. It is essential for the invention that the keyboard B be independent of the coupling to permit that the keyboard A shall always be playable.

It will be understood that instead of an octave coupling any other musical interval may be used, for instance fifths, thirds, and so on.

Referring now to the last modification shown in Figs. 9-12 there are also in this case the keys of the rear or additional keyboard B operated by the intermediary of bent, obliquely arranged levers, with the interval of an octave or another musical interval relatively to the tones produced by the corresponding keys of the front keyboard. lVhile in the above described constructional forms bent, oblique lever such as 9 are used, these levers are dispensed with in the constructional form shown in Figs. 912.

There are again the two keyboards A and B and the keys of the front keyboard are connected with the keys of the rear keyboard solely by the obliquely arranged levers 16 which, in the example shown, connect keys pertaining to tones separated from one another by an octave etc. Only one'such lever is shown in Fig. 10, but I wish it to be understood that also the other keys,-except the set at the righthand end of the front board and the set at the lefthand end of the rear board, are connected with one another in that manner. The keys of the, rear board can also in'this case be actuated independently of the keys of the front-board, the catch being, in this case not inserted between the key levers 7 and the transmission levers 16, but being inserted in that case in which the res ective tone, with an interval of an octave or the like, is to be produced also by the corresponding front key, the fundamental tone and the octave etc., tone being now produced at the same time.

There is a catch lever 30 between thetwo keys of each pair of keys pertaining to the two keyboards, and every lever is guided in a guide member 31 which is preferably adjustable. All these guide members are located upon a horizontal ledge 34 madev preferably of bronze, which in turn is supported on hearing members 32 in such a manner that it can be turned forwardly and rearwardly thereon.

In the bot-tom face of the key 7 is an adjusting screw 35, the head of which bears upon the rear end of the catch lever 30, and in this lever is provided an adjusting screw 36, the head of which is located below this lever and bears upon the front end of the lever 16. When the catch 13 engagesthe lever 30 and the key 1 is depressed, this movement is transmitted by said members 13 and 30, as well as by the screw 36, to the lever 16 which is now also actuated in such a way that the tone corresponding to the octave etc., interval is produced. 3 v

The catch 13 extends through a slot of the lever 30. When the catch is in the position shown in Fig. 11, it is inoperative, that is to say, it cannot engage the lever 30, but when the pedal is operated so as to move the catch rearwardly and make it engage the lever 30 it will transmit the movement of the key 1 to the octave tone hammer, as described. The catch 13 is turnably mounted upon the key lever 2 and is, besides, movably connected with a bracket 38 by the intermediary of a member 37 that is hinged to the catch, as well as to said bracket, the arrangement being such that when the pedal is not actuated and the key 1 is depressed, now the catch is kept remote from the lever 30 so that solely the tone pertaining to that key 1 is produced. The intermediate member hinged to the bracket 38 is also movably connected with a rod 39 extending rearwardly to the bellcrank lever 40, with the one arm of which it is connected, whereas the other arm of this lever is connected with the push member 41 by the intermediary of a regulating screw. When both keyboards are used in the normal way the catch 13 is and'remains uncoupled from the lever 30, but whenthe pedal is actuated in order to produce also the octave-etc.- sounds, the push-member l1 is moved upwardly and turns the bell-crank lever 40 so as to pull the rod 39 to the left (Figs. 11 and 12) whereby the catch 13 will be drawn towards and over the lever 30, and the respective key or keys 1 will be coupled with the corresponding levers 16 that actuate the hammers producing the octave-etc.-tones, as already described. When then, afterwards, the pedal is released, that coupling is broken and the position of the members concerned will again be that shown in said figures.

I We claim:

1. A keyboard instrument, comprising, .in combination, two keyboards arranged behind one another, means adapted to transmit the depression of any one of the front keyboard also to hammers differentiated from those pertaining normally to the depressed front rear keyboard to the hammer mechanism,

substantially as set forth.

2. A keyboard instrument, comprising, in combination, two keyboards arranged behind one another, means adapted to transmit the depression of any one of the front keyboard also to hammers differentiated from those pertaining normally to the depressed front board key or keys by a musical interval, said means comprising also a member adapted to be actuated by keys of both boards and extending obliquely from the keys of the rear keyboard to the hammer mechanism pertaining to the interval hammers located righthand from the hammers producing the tones pertaining to the depressed key or keys of the front keyboard, substantially as set forth.

3. A keyboard instrument, comprising, in combination, two keyboards arranged behind one another, means adapted to transmit the depression of any one of the front keyboard also to hammers differentiated from those pertaining normally to the depressed front board key or keys by a musical interval, said means comprising also a member adapted to be actuated by keys of both boards and extending obliquely from the keys of the rear keyboard to the hammer mechanism, and

.a coupling member adapted to be actuated by the pedal of the instrument, substantially as set forth.

4. A keyboard instrument, comprising, in combination, two keyboards arranged behind one another,'means adapted to transmit the depression of any one of the front keyboard also to hammers differentiated from those pertaining normally to the depressed front board key or keys by a musical interval, said means comprising also a double-armed lever adapted to be actuated by keys of both boards, and transmitting members extending obliquely from the keys of the rear keyboard to the hammer mechanism, substantially as set forth.

5. A keyboard instrument, comprising, in combination, two keyboards arranged behind one another, means adapted to transmit the depression of any one of the front keyboard also to hammers differentiated from those pertaining normally to the depressed front board key or keys by a musical interval, said means comprising also a member adapted to be subjected to a pull by keys of both boards, and transmitting members extendin obliquely from the keys of the rear keyboard to the hammer mechanism, substantially as set forth. I

6. A keyboard instrument, comprising, in combination, two keyboards arranged behind one another, means adapted to transmit the depression of any one of the front-keyboard also to hammers differentiated from those pertaining normally to the depressed front board key or keys by a musical interval, said means comprising also a member adapted to be actuated by keys of both boards and extending obliquely from the keys of the rear keyboard to the hammer mechanism, and a catch member adapted to be inserted between the transmitting members of both keyboards, substantially as set forth.

'7. A keyboard instrument, comprising, in combination, two keyboards arranged behind one another, means adapted to transmit the depression of any one of the front keyboard also to hammers differentiated from those pertaining normally to the depressed front board key or keys by a musical interval, said means comprising also a member adapted to be actuated by keys of both boards and extending obliquely from the keys of the rear keyboard to the hammer mechanism, and rear transmitting members forming parts of the hammer-actuating mechanism and presenting more than one power-transmitting point for the transmitting members extending from the keyboards to the hammer-actuating' mechanism, substantially as set forth. 8. A keyboard instrument, comprising, in combination, two keyboards arranged behind one another, means adapted to transmit the depression of any one of the front keyboard also to hammers differentiated from those pertaining normally to the depressed front bcarc key or keys by a musical interval, said means comprising also a member adapted to be actuated by keys of both boards and eX- tending obliquely from the keys of the rear keyboard to the hammer mechanism, and rear transmitting members forming parts of the hammer-actuating mechanism of all those tones that are differentiated by a musical interval from those produced by the depressed front keys, substantially as set forth.

9. A keyboard instrument having two keyboards located behind one another, and an octave coupling, comprising, in combination with said keyboards and said coupling, catches and levers so arranged as to be adapted to be coupled with said catches; obliquely arranged transmitting members upon which said levers can act, and means for making the said catches engage the said levers, substantially and for the purpose set forth.

10. A keyboard instrument having two keyboards located behind one another, and an octave coupling, comprising, in combination with said keyboards and said coupling, catches and levers so arranged as to be adapted to be coupled with said catches; supporting members for said levers, and brackets for said supporting members, these brackets being affixed upon the bottom plate of the instrument, substantially as set forth.

11. A keyboard instrument having two keyboards located behind one another, and an octave coupling, comprising, in combination with said keyboards and said coupling, catches and levers so arranged as to be adapted to be coupled with said catches; adjust ing screws provided in said levers in such posit-ions that the said levers can be adjusted with respect to the keys levers of the rear keyboards, as well as to the transmitting members to which they are attached; obliquely arranged transmitting members upon which said levers can act, and means for making the said catches engage the said levers, substantially and for the purpose set forth.

12-. A keyboard instrument having two keyboards located behind one another, and an octave coupling, comprising, in combination with said keyboards and said coupling, catches hinged to the front key levers and adapted to be actuated by the pedal of the instrument; levers hinged to movable supporting members and extending through slots of said catches; rods extending from said catches to the hammeractuating mechanism; movable connecting members between said rods and the catches, turnable supports for said connecting members; obliquely arranged transmitting members upon which said levers can act, and means for making the said catches engage the said levers, substantially and for the purpose set forth.

13. A keyboard instrument having two keyboards located behind one another. and an octave coupling, comprising, in combination with said keyboards and said coupling, catches hinged to the front key levers and adapted to be actuated by the pedal of the instrument; levers hinged to movable supporting members and extending through slots of said catches; rods extending from said catches to the hammer-actuating mechanism; bell-crank levers inserted between said mechanism and said rods, and means for moving these rods automatically back into their normal position in which the said levers and the said catches are disengaged from one another; obliquely arranged transmitting members upon which said levers can act, and means for making the said catches engage the said levers, substantially and for the purpose set forth.

In testimony whereof we aflix our signatures.

EMANUEL MOOR.

CARL BECHSTEIN, JR.

HANS JOACHIM GRAVENSTEIN. 

